Mobile terminal

ABSTRACT

A mobile terminal including a first frame; a second frame including a third rear portion coupled to a rear face of the first frame and being movable in a first direction, and including a roller disposed at an end in the first direction of the third rear portion; a third frame coupled to a rear face of the third rear portion and being movable in the first direction; a flexible display panel surrounding the roller and having one end on a front face of the first frame and another end disposed on the third frame; a driving unit configured to drive the second frame from the first frame in the first direction or in a second direction reverse to the first direction; and a spring member connecting the second frame to the third rear portion of the second frame and configured to provide a constant force in the second direction to the third frame.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of an earlier filing date and priority to PCT International Application No. PCT/KR2020/000362 filed on Jan. 9, 2020, the contents of which are incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates to a mobile terminal in which a screen exposed from a front face of the mobile terminal is expandable.

Discussion of the Related Art

Terminals may be generally classified as mobile/portable terminals or stationary terminals according to their mobility. Mobile terminals may also be classified as handheld terminals or vehicle mounted terminals according to whether or not a user can directly carry the terminal.

A display device is a device having a function of receiving, processing, and displaying a video that a user may watch. For example, the display device receives a broadcast selected by the user from broadcast signals transmitted from a broadcasting station, separates a video signal from the received signals, and displays the separated video signal on a display.

In recent years, because of a development of a broadcasting technology and a network technology, functions of the display device have also been considerably diversified, and a performance of the device has been improved accordingly. That is, the display device has been developed to provide not only broadcast contents but also various other contents to the user. For example, the display device may provide game play, music listening, internet shopping, user customized information, and the like using various applications as well as programs received from the broadcasting station. In order to perform such extended functions, the display device may be basically connected to other devices or networks using various communication protocols, and may provide the user with a ubiquitous computing environment. In other words, the display device has evolved into a smart device that enables connectivity to a network and continuous computing.

In one example, recently, the mobile terminal is providing a larger screen to the user. The mobile terminal may provide a large screen that is folded in one direction as a foldable mobile terminal or provide a large screen that is expanded or contracted in one direction as a rollable mobile terminal.

SUMMARY OF THE INVENTION

The present disclosure relates to a mobile terminal capable of expanding a screen exposed from a front face thereof using a roller, and has an object of preventing a wrinkle of a flexible display panel outputting the screen.

One aspect of the present disclosure proposes a mobile terminal including a first frame, a second frame including a third rear portion disposed on a rear face of the first frame and coupled to the rear face of the first frame in a manner of being movable in a first direction, and a first roller disposed at an end in the first direction of the third rear portion, a third frame disposed on a rear face of the third rear portion and coupled to the rear face of the third rear portion in a manner of being movable in the first direction, a flexible display panel disposed to surround the first roller and having one end disposed on a front face of the first frame and the other end disposed on the third frame, a driving unit for driving the second frame from the first frame in the first direction or in a reverse direction of the first direction, and a spring member for providing a constant force in the reverse direction of the first direction to the third frame.

In one implementation, the spring member may include a fixed shaft, and a spiral spring disposed to be wound around or unwound from the fixed shaft, wherein the spiral spring generates a constant attractive force while being wound around or unwound from the fixed shaft.

In one implementation, the spring member may be disposed such that the fixed shaft is fixed to the third frame, an end of the spiral spring is fixed to the third rear portion, and the spiral spring is wound in the first direction, or that the fixed shaft is fixed to the third rear portion, the end of the spiral spring is fixed to the third frame, and the spiral spring is unwound in the first direction.

In one implementation, the third rear portion may include a guide groove recessed in the rear face of the third rear portion in a direction of a front face of the third rear portion such that the spiral spring is disposed on the rear face of the third rear portion.

In one implementation, the third rear portion may include a slit for communicating the rear face and a front face of the third rear portion with each other such that the spiral spring is disposed on the front face of the third rear portion.

In one implementation, when the spiral spring provides the constant attractive force in a state of being unwound by a length equal to or greater than a first length, the spring member may connect the third frame and the third rear portion with each other such that the spiral spring is maintained in the state of being unwound by the length equal to or greater than the first length.

In one implementation, the third frame may be maintained in a state of being maximally moved in the reverse direction of the first direction with respect to the third rear portion in a first state, wherein the spring member may connect the third frame and the third rear portion with each other in the state where the spiral spring is unwound by the length equal to or greater than the first length in the first state.

In one implementation, when the spiral spring provides the constant attractive force in a state of being unwound by a length equal to or less than a second length, the spring member may connect the third frame and the third rear portion with each other such that the spiral spring is maintained in the state of being unwound by the length equal to or less than the second length.

In one implementation, the third frame may be maintained in a state of being maximally moved in the first direction with respect to the third rear portion in a second state, wherein the spring member may connect the third frame and the third rear portion with each other in the state where the spiral spring is unwound by the length equal to or less than the second length in the second state.

In one implementation, the fixed shaft may be a shaft of the first roller.

In one implementation, the spring member may include a wire for connecting an end of the spiral spring and the third frame with each other, and a shaft fixed to the third rear portion and surrounded by the wire such that both ends of the wire are directed in the first direction.

In one implementation, the shaft may include a bearing rotating in response to a movement of the wire.

In one implementation, the first roller may include a first region rotating in contact with a rear face of the flexible display panel, and a second region wound by the spiral spring.

In one implementation, in the first roller, a diameter of the second region may be equal to or smaller than a diameter of the first region in a state where the spiral spring is maximally wound.

In one implementation, the first roller may not rotate in the second region.

According to the above object, the mobile terminal according to an embodiment may prevent a user from recognizing a luminance deviation in dividing a large screen through two drivers and outputting an image.

In addition, the mobile terminal according to an embodiment may prevent the user from recognizing a time difference of the image output in dividing the large screen through the two drivers and outputting the image.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the disclosure and together with the description serve to explain the principle of the disclosure. In the drawings:

FIG. 1 is a block diagram of a mobile terminal in accordance with the present disclosure.

FIG. 2 is an exploded perspective view of a mobile terminal according to one embodiment.

FIG. 3 shows perspective views respectively illustrating a first state and a second state viewed from one side of a mobile terminal according to one embodiment.

FIG. 4 shows rear face views respectively illustrating a first state and a second state of a mobile terminal according to one embodiment.

FIG. 5 shows cross-sectional views respectively taken along a line A-A and a line B-B of FIG. 3.

FIG. 6 is a rear face view of some components of a mobile terminal according to one embodiment.

FIG. 7 is an exploded view of some components of a mobile terminal according to one embodiment.

FIGS. 8 and 9 are views for describing some components of a mobile terminal according to one embodiment.

FIG. 10 shows an enlarged view and a cross-sectional view of a portion C in FIG. 6.

FIG. 11 shows an enlarged view and a cross-sectional view of a portion D in FIG. 6.

FIG. 12 is a front view of some components of a mobile terminal according to one embodiment.

FIG. 13 is a cross-sectional view of some components of a mobile terminal according to one embodiment.

FIG. 14 is a rear face view of some components of a mobile terminal according to one embodiment.

FIG. 15 is a cross-sectional view taken along a line G-G′ in FIG. 14.

FIG. 16 is a view for describing some components of a mobile terminal according to one embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Description will now be given in detail according to exemplary embodiments disclosed herein, with reference to the accompanying drawings. For the sake of brief description with reference to the drawings, the same or equivalent components may be provided with the same reference numbers, and description thereof will not be repeated. In general, a suffix such as “module” and “unit” may be used to refer to elements or components. Use of such a suffix herein is merely intended to facilitate description of the specification, and the suffix itself is not intended to give any special meaning or function. In the present disclosure, that which is well-known to one of ordinary skill in the relevant art has generally been omitted for the sake of brevity. The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings.

It will be understood that although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another. It will be understood that when an element is referred to as being “connected with” another element, the element can be connected with the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly connected with” another element, there are no intervening elements present.

A singular representation may include a plural representation unless it represents a definitely different meaning from the context. Terms such as “include” or “has” are used herein and should be understood that they are intended to indicate an existence of several components, functions or steps, disclosed in the specification, and it is also understood that greater or fewer components, functions, or steps may likewise be utilized.

FIG. 1 is a block diagram of a mobile terminal in accordance with the present disclosure. The mobile terminal 100 is shown having components such as a wireless communication unit 110, an input unit 120, a sensing unit 140, an output unit 150, an interface unit 160, a memory 170, a controller 180, and a power supply unit 190. It is understood that implementing all of the illustrated components is not a requirement, and that greater or fewer components may alternatively be implemented. Referring now to FIG. 1, the mobile terminal 100 is shown having wireless communication unit 110 configured with several commonly implemented components. It is understood that implementing all of the illustrated components is not a requirement, and that greater or fewer components may alternatively be implemented.

More specifically, the wireless communication unit 110 typically includes one or more modules which permit communications such as wireless communications between the mobile terminal 100 and a wireless communication system, communications between the mobile terminal 100 and another mobile terminal, communications between the mobile terminal 100 and an external server. Further, the wireless communication unit 110 typically includes one or more modules which connect the mobile terminal 100 to one or more networks.

To facilitate such communications, the wireless communication unit 110 includes one or more of a broadcast receiving module 111, a mobile communication module 112, a wireless Internet module 113, a short-range communication module 114, and a location information module 115. Regarding the wireless communication unit 110, the broadcast receiving module 111 is typically configured to receive a broadcast signal and/or broadcast associated information from an external broadcast managing entity via a broadcast channel. The broadcast channel may include a satellite channel, a terrestrial channel, or both. In some embodiments, two or more broadcast receiving modules 111 may be utilized to facilitate simultaneously receiving of two or more broadcast channels, or to support switching among broadcast channels.

The mobile communication module 112 can transmit and/or receive wireless signals to and from one or more network entities. Typical examples of a network entity include a base station, an external mobile terminal, a server, and the like. Such network entities form part of a mobile communication network, which is constructed according to technical standards or communication methods for mobile communications (for example, Global System for Mobile Communication (GSM), Code Division Multi Access (CDMA), CDMA2000(Code Division Multi Access 2000), EV-DO(Enhanced Voice-Data Optimized or Enhanced Voice-Data Only), Wideband CDMA (WCDMA), High Speed Downlink Packet access (HSDPA), HSUPA(High Speed Uplink Packet Access), Long Term Evolution (LTE), LTE-A(Long Term Evolution-Advanced), and the like). Examples of wireless signals transmitted and/or received via the mobile communication module 112 include audio call signals, video (telephony) call signals, or various formats of data to support communication of text and multimedia messages.

The wireless Internet module 113 is configured to facilitate wireless Internet access. This module may be internally or externally coupled to the mobile terminal 100. The wireless Internet module 113 may transmit and/or receive wireless signals via communication networks according to wireless Internet technologies.

Examples of such wireless Internet access include Wireless LAN (WLAN), Wireless Fidelity (Wi-Fi), Wi-Fi Direct, Digital Living Network Alliance (DLNA), Wireless Broadband (WiBro), Worldwide Interoperability for Microwave Access (WiMAX), High Speed Downlink Packet Access (HSDPA), HSUPA (High Speed Uplink Packet Access), Long Term Evolution (LTE), LTE-A (Long Term Evolution-Advanced), and the like. The wireless Internet module 113 may transmit/receive data according to one or more of such wireless Internet technologies, and other Internet technologies as well.

In some embodiments, when the wireless Internet access is implemented according to, for example, WiBro, HSDPA, HSUPA, GSM, CDMA, WCDMA, LTE, LTE-A and the like, as part of a mobile communication network, the wireless Internet module 113 performs such wireless Internet access. As such, the Internet module 113 may cooperate with, or function as, the mobile communication module 112.

The short-range communication module 114 is configured to facilitate short-range communications. Suitable technologies for implementing such short-range communications include BLUETOOTH™, Radio Frequency IDentification (RFID), Infrared Data Association (IrDA), Ultra-WideBand (UWB), ZigBee, Near Field Communication (NFC), Wireless-Fidelity (Wi-Fi), Wi-Fi Direct, Wireless USB (Wireless Universal Serial Bus), and the like. The short-range communication module 114 in general supports wireless communications between the mobile terminal 100 and a wireless communication system, communications between the mobile terminal 100 and another mobile terminal 100, or communications between the mobile terminal and a network where another mobile terminal 100 (or an external server) is located, via wireless area networks. One example of the wireless area networks is a wireless personal area network.

The location information module 115 is generally configured to detect, calculate, derive or otherwise identify a position of the mobile terminal. As an example, the location information module 115 includes a Global Position System (GPS) module, a Wi-Fi module, or both. If desired, the location information module 115 may alternatively or additionally function with any of the other modules of the wireless communication unit 110 to obtain data related to the position of the mobile terminal. As one example, when the mobile terminal uses a GPS module, a position of the mobile terminal may be acquired using a signal sent from a GPS satellite. As another example, when the mobile terminal uses the Wi-Fi module, a position of the mobile terminal can be acquired based on information related to a wireless access point (AP) which transmits or receives a wireless signal to or from the Wi-Fi module.

The input unit 120 includes a camera 121 for obtaining images or video, a microphone 122, which is one type of audio input device for inputting an audio signal, and a user input unit 123 (for example, a touch key, a push key, a mechanical key, a soft key, and the like) for allowing a user to input information. Data (for example, audio, video, image, and the like) is obtained by the input unit 120 and may be analyzed and processed by controller 180 according to device parameters, user commands, and combinations thereof.

Such cameras 121 may process image frames of still pictures or video obtained by image sensors in a video or image capture mode. The processed image frames can be displayed on the display unit 151 or stored in memory 170. In some cases, the cameras 121 may be arranged in a matrix configuration to permit a plurality of images having various angles or focal points to be input to the mobile terminal 100. As another example, the cameras 121 may be located in a stereoscopic arrangement to acquire left and right images for implementing a stereoscopic image.

The microphone 122 is generally implemented to permit audio input to the mobile terminal 100. The audio input can be processed in various manners according to a function being executed in the mobile terminal 100. If desired, the microphone 122 may include assorted noise removing algorithms to remove unwanted noise generated in the course of receiving the external audio.

The user input unit 123 is a component that permits input by a user. Such user input may enable the controller 180 to control operation of the mobile terminal 100. The user input unit 123 may include one or more of a mechanical input element (for example, a key, a button located on a front and/or rear surface or a side surface of the mobile terminal 100, a dome switch, a jog wheel, a jog switch, and the like), or a touch-sensitive input, among others. As one example, the touch-sensitive input may be a virtual key or a soft key, which is displayed on a touch screen through software processing, or a touch key which is located on the mobile terminal at a location that is other than the touch screen. On the other hand, the virtual key or the visual key may be displayed on the touch screen in various shapes, for example, graphic, text, icon, video, or a combination thereof.

The sensing unit 140 is typically implemented using one or more sensors configured to sense internal information of the mobile terminal, the surrounding environment of the mobile terminal, user information, and the like. If desired, the sensing unit 140 may alternatively or additionally include other types of sensors or devices, such as a touch sensor, an acceleration sensor, a magnetic sensor, a G-sensor, a gyroscope sensor, a motion sensor, an RGB sensor, an infrared (IR) sensor, a finger scan sensor, a ultrasonic sensor, an optical sensor (for example, camera 121), a microphone 122, a battery gauge, an environment sensor (for example, a barometer, a hygrometer, a thermometer, a radiation detection sensor, a thermal sensor, and a gas sensor, among others), and a chemical sensor (for example, an electronic nose, a health care sensor, a biometric sensor, and the like), to name a few. The mobile terminal 100 may be configured to utilize information obtained from sensing unit 140, and in particular, information obtained from one or more sensors of the sensing unit 140, and combinations thereof.

The output unit 150 is typically configured to output various types of information, such as audio, video, tactile output, and the like. The output unit 150 is shown having a display unit 151, an audio output module 152, a haptic module 153, and an optical output module 154. The display unit 151 may have an inter-layered structure or an integrated structure with a touch sensor in order to facilitate a touch screen. The touch screen may provide an output interface between the mobile terminal 100 and a user, as well as function as the user input unit 123 which provides an input interface between the mobile terminal 100 and the user.

The audio output module 152 is generally configured to output audio data. Such audio data may be obtained from any of a number of different sources, such that the audio data may be received from the wireless communication unit 110 or may have been stored in the memory 170. The audio data may be output during modes such as a signal reception mode, a call mode, a record mode, a voice recognition mode, a broadcast reception mode, and the like. The audio output module 152 can provide audible output related to a particular function (e.g., a call signal reception sound, a message reception sound, etc.) performed by the mobile terminal 100. The audio output module 152 may also be implemented as a receiver, a speaker, a buzzer, or the like.

A haptic module 153 can be configured to generate various tactile effects that a user feels, perceive, or otherwise experience. A typical example of a tactile effect generated by the haptic module 153 is vibration. The strength, pattern and the like of the vibration generated by the haptic module 153 can be controlled by user selection or setting by the controller. For example, the haptic module 153 may output different vibrations in a combining manner or a sequential manner.

An optical output module 154 can output a signal for indicating an event generation using light of a light source. Examples of events generated in the mobile terminal 100 may include message reception, call signal reception, a missed call, an alarm, a schedule notice, an email reception, information reception through an application, and the like.

The interface unit 160 serves as an interface with various types of external devices that can be coupled to the mobile terminal 100. The interface unit 160, for example, may include any of wired or wireless ports, external power supply ports, wired or wireless data ports, memory card ports, ports for connecting a device having an identification module, audio input/output (I/O) ports, video I/O ports, earphone ports, and the like. In some cases, the mobile terminal 100 may perform assorted control functions associated with a connected external device, in response to the external device being connected to the interface unit 160.

The memory 170 is typically implemented to store data to support various functions or features of the mobile terminal 100. For instance, the memory 170 may be configured to store application programs executed in the mobile terminal 100, data or instructions for operations of the mobile terminal 100, and the like. Some of these application programs may be downloaded from an external server via wireless communication. Other application programs may be installed within the mobile terminal 100 at time of manufacturing or shipping, which is typically the case for basic functions of the mobile terminal 100 (for example, receiving a call, placing a call, receiving a message, sending a message, and the like). It is common for application programs to be stored in the memory 170, installed in the mobile terminal 100, and executed by the controller 180 to perform an operation (or function) for the mobile terminal 100.

The controller 180 typically functions to control overall operation of the mobile terminal 100, in addition to the operations associated with the application programs. The controller 180 may provide or process information or functions appropriate for a user by processing signals, data, information and the like, which are input or output by the various components depicted in FIG. 1, or activating application programs stored in the memory 170.

The power supply unit 190 can be configured to receive external power or provide internal power in order to supply appropriate power required for operating elements and components included in the mobile terminal 100. The power supply unit 190 may include a battery, and the battery may be configured to be embedded in the terminal body, or configured to be detachable from the terminal body.

Some or more of the components may be operated cooperatively to embody an operation, control or a control method of the mobile terminal in accordance with embodiments of the present disclosure. Also, the operation, control or control method of the mobile terminal may be realized on the mobile terminal by driving of one or more application problems stored in the memory 170.

FIG. 2 is an exploded perspective view of a mobile terminal according to one embodiment, FIG. 3 shows perspective views respectively illustrating a first state and a second state viewed from one side of a mobile terminal according to one embodiment, and FIG. 4 shows rear face views respectively illustrating a first state and a second state of a mobile terminal according to one embodiment. Further, FIG. 5 shows cross-sectional views respectively taken along a line A-A and a line B-B of FIG. 3. In these drawings, FIGS. 3A, 4A, and 5A show a first state of the mobile terminal, and FIGS. 3B, 4B, and 5B show a second state of the mobile terminal.

As shown, a mobile terminal 100 in a first state is contracted, and has a smaller size than the mobile terminal 100 in a second state. In addition, a size of a display unit 151 located disposed on a front face of the mobile terminal 100 also becomes smaller than that of the display unit 151 in the second state. The mobile terminal 100 of the first state is expanded in a first direction D1 to be in the second state. In the second state, a size of the mobile terminal 100 and a size of the front face of the display unit 151 become larger than that in the first state as shown in FIG. 3B, and a size of the rear face of the display unit 151 is reduced as shown in FIG. 4B. That is, the display unit 151 positioned on the rear face of the mobile terminal 151 in the first state moves to the front face of the mobile terminal 100 in the second state.

In a following description, a direction in which the mobile terminal 100 and the display 151 thereof are extended or enlarged is referred to as a first direction D1, a direction in which the mobile terminal 100 and the display 151 thereof are contracted or retracted, or reduce to be converted into the first state from the second state is referred to as a second direction D2, and a direction perpendicular to the first and second directions D1 and D2 is referred to as a third direction.

As such, the display unit may use a flexible display unit 151 that may be bent such that the position of the display unit may be varied. The flexible display is a lightweight, unbreakable, and durable display that is built on a thin and flexible substrate that may be bent, crooked, folded, twisted, or rolled while retaining properties of a conventional flat panel display.

In addition, an electronic paper is a display technology to which properties of general ink are applied. The electronic paper may be different from the conventional flat panel display in using reflected light. The electronic paper may change information using a twisted ball or electrophoresis using a capsule.

In a state in which the flexible display unit 151 is not deformed (e.g., a state of having an infinite curvature radius, hereinafter referred to as a basic state), a display region of the flexible display unit 151 becomes flat. In a state in which the flexible display unit 151 is deformed by an external force from the basic state (e.g., a state of having a finite radius of curvature, hereinafter referred to as a deformed state), the display region may become a curved face. As shown, information displayed in the deformation state may be visual information output on the curved face. Such visual information is implemented by independently controlling light emission of sub-pixels arranged in a matrix. The sub-pixel refers to a minimum unit for implementing one color.

The flexible display unit 151 may be in a curved state (e.g., a vertically or horizontally curved state) rather than a flat state in the basic state. In this case, when the external force is applied to the flexible display unit 151, the flexible display unit 151 may be deformed into the flat state (or a less curved state) or more curved state.

The flexible display unit 151 may be combined with a touch sensor to implement a flexible touch screen. When a touch is made on the flexible touch screen, the controller 180 (see FIG. 1) may perform control corresponding to such touch input. The flexible touch screen may be configured to detect the touch input in the deformed state as well as in the basic state.

The touch sensor detects the touch (or touch input) applied on the touch screen using at least one of various touch schemes such as a resistive film scheme, a capacitance scheme, an infrared scheme, an ultrasonic wave scheme, a magnetic field scheme, and the like. As an example, the touch sensor may be configured to convert a change in pressure applied on a specific portion of the touch screen, capacitance generated at the specific portion, or the like into an electrical input signal. The touch sensor may be configured such that a touch object applying a touch on the touch screen may detect touched position and area on the touch sensor, a pressure during the touch, a capacitance during the touch, and the like.

Further, the mobile terminal 100 may have a deformation detection means for detecting the deformation of the flexible display unit 151. Such deformation detection means may be included in the sensing unit 140 (see FIG. 1). The deformation detection means may be disposed in the flexible display unit 151 or a case (first to second frames 101 to 102 to be described later) to detect information related to the deformation of the flexible display unit 151. In this connection, the information related to the deformation may include a direction in which the flexible display unit 151 is deformed, a degree of the deformation, a deformed position, a deformed time, an acceleration at which the deformed flexible display unit 151 is restored, and the like. In addition, the information related to the deformation may be various information that may be detected due to the bending of the flexible display unit 151.

In addition, the controller 180 may change information displayed on the flexible display unit 151 or generate a control signal for controlling a function of the mobile terminal 100 based on the information related to the deformation of the flexible display unit 151 detected by the deformation detection means.

The state conversion (first or second state) of the flexible display unit 151, i.e., the size change at the front and rear faces of the mobile terminal 100 of the display unit 151 based on the size change of the mobile terminal 100 may be performed manually by a force applied by the user, but may be not limited to such manual scheme. For example, when the mobile terminal 100 or the flexible display unit 151 is in the first state, the mobile terminal 100 or the flexible display unit 151 may be converted into the second state by the user or an application command without the external force applied by the user. As such, in order for the flexible display unit 151 to be automatically deformed without the external force, the mobile terminal 100 may include a driving unit 200 to be described later.

The flexible display unit 151 of the present disclosure is bent 180 degrees while being rolled on a side of the mobile terminal 100 in the first direction. Thus, a portion of the display unit 151 is disposed on the front face of the mobile terminal 100 based on such side, and the other portion thereof is disposed on the rear face of the mobile terminal 100. A portion of the display unit 151 located on the front face of the mobile terminal 100 may be fixed to the front face so as not to move. Further, the other portion thereof located on the rear face of the mobile terminal 100 may be movable to the rear face.

In addition, the display unit 151 may be rolled on or released from the side. Accordingly, the portion disposed on the rear face of the mobile terminal 100 moves, so that the size of the portion disposed on the front face of the mobile terminal 100 may be adjusted. Since the area of the flexible display unit 151 is determined and the flexible display unit 151 is formed of one continuous body, an area of the portion on the rear face decreases as an area of the portion on the front face increases. Such a display unit 151 may be rolled in a second frame 102, which is movable relative to a first frame 101 to be described later, more correctly, on one of sides of the second frame 102. The display unit 151 may be withdrawn or pulled out from or inserted or pushed into the second frame 102 while being rolled in the second frame 102 along a moving direction of the second frame 102 to adjust the area of the display unit 151 on the front face of the mobile terminal 100. Such operation will be described in more detail below along with other relevant components of the mobile terminal 100.

Typically, an antenna is disposed in the case or the housing of the mobile terminal 100, but a portion where the antenna is installed in the case or the housing may be limited because of the flexible display unit 151 that covers not only the front face of the mobile terminal 100 but also the rear face thereof. For this reason, the antenna may be implemented on the flexible display unit 151. An antenna on display (AOD) is an antenna in which a transparent film is formed by stacking an electrode layer and a dielectric layer that have patterns engraved thereon, respectively. The antenna on display may be implemented thinner than an antenna implemented using a laser direct structuring (LDS) technology using a conventional copper nickel plating scheme, so that the antenna on display may not be exposed to the outside without affecting a thickness. In addition, the antenna on display may transmit and receive a signal directly to or from the display unit 151. Accordingly, the antenna on display may be used in the mobile terminal 100 in which the display unit 151 is located on the both faces of the mobile terminal 100 as in the present disclosure.

Referring to FIGS. 2 to 5, a detailed configuration of the mobile terminal 100 according to the present disclosure will be described below. In the following description, FIG. 2 illustrating an overall configuration is referred to, and FIGS. 3 to 5 are referred to describe detailed features of corresponding components in the first and second states of the mobile terminal 100.

The mobile terminal 100 of the present disclosure includes frames 101 and 102 in which components are mounted, and the frames 101 and 102 of the present disclosure may vary in size in the first direction as shown in FIG. 2. One or more frames 101 and 102 move relative to each other, and sizes thereof may vary in the first direction. Electronic components are mounted in the frames 101 and 102, and the flexible display unit 151 is located outside the frames 101 and 102.

Since the mobile terminal 100 of the present disclosure includes the flexible display unit 151, the flexible display unit 151 may be combined in a form surrounding front faces and rear faces of the frames 101 and 102. The frame may include the first frame 101 and the second frame 102 moving in the first direction with respect to the first frame 101. The first frame 101 and the second frame 102 include front portions, rear portions, and side portions, respectively, and are coupled to each other. Thus, the mobile terminal 100 may have a hexahedral outer shape by such coupled first and second frames 101 and 102.

First, the first frame 101 corresponds to a main body of the mobile terminal 100, and may have a space therein for accommodating various components. In addition, the first frame 101 may accommodate the second frame 102 movably coupled to the first frame 101 in such a space. More specifically, as shown in FIGS. 2 and 5, the first frame 101 may include a first front portion 1011 disposed at a front portion of the mobile terminal 100 and supporting the front face of the display unit 151 and a first rear portion 1012 disposed at a rear portion of the mobile terminal and on which various components are mounted.

The first front portion 1011 and the first rear portion 1012 may be spaced apart from each other at a predetermined spacing to define a predetermined space therebetween, and may be connected to each other by a side portion 1014. The side portion 1014 may be integrally formed with the first rear portion 1012 or the first front portion 1011. The camera 121, the audio output module 152, and the input/output terminal 161, the controller 180, and the power supply unit 190 may be accommodated as components of the mobile terminal 100 in the space in the first frame 101. For example, the controller 180 may be a circuit board 181 including a processor and an electronic circuit for controlling the operation of the mobile terminal, and the power supply unit 190 may be a battery 191 and related components. In addition, the driving unit 200 that controls the slide movement of the second frame 102, which will be described later, may also be accommodated in the first frame 101.

As described above, the display unit 151 has the continuous body, and thus, may be disposed on both the front face and the rear face of the mobile terminal 100 while being rolled in the mobile terminal 100. The display unit 151 may include the front face positioned at the front face of the mobile terminal 100, the rear face positioned at the rear face of the mobile terminal 100, and the side face positioned between the front face and the rear face thereof and surrounding the side face of the mobile terminal. The front face and the rear face of the display unit 151 are flat, and the side face of the display unit 151 may form a curved face. When the flexible display unit 151 may be damaged when being bent. Thus, the flexible display unit 151 may be formed to be bent with a predetermined curvature.

The display unit 151 may be divided into a fixed portion and a variable portion. The fixed portion means a portion fixed to the frame. Because of being fixed to the frame, the fixed portion maintains a constant shape without changing a bending degree. On the other hand, the variable portion means a portion in which a bending angle or a position of the bent portion changes. The variable portion in which the position or bending angle of the bent portion changes requires a structure for supporting a rear face of the variable portion in response to the change. A first region 1511 of the display unit 151 may be coupled to the first front portion 1011 corresponding to the front face of the mobile terminal 100.

In one example, as illustrated well in FIG. 4, the various physical input units 120 and the sensing unit 140 for manipulation of the mobile terminal 100 may be located on the first rear portion 1012, and the display unit 151 may be disposed only on a second rear portion 1013. The first rear portion 1012 is not overlapped with the flexible display unit 151 regardless of the state of the mobile terminal, and is always exposed to the outside. Thus, the input unit 120 such as various buttons, a switch, the camera 121, and a flash, and the sensing unit 140 such as a proximity sensor 141 may be disposed on the first rear portion 1012. In a usual bar-type terminal, a display unit is provided only on a front face of a terminal. Therefore, in order for a user to photograph an object on the other side while viewing the display unit, a main camera is disposed on a rear face of the terminal. In one example, in order for the user to photograph while viewing himself through the display unit, an auxiliary camera is additionally required on the front face of the terminal.

However, in the mobile terminal 100 according to the present disclosure, the display unit 151 is located on both the front face and the rear face of the terminal. Therefore, when the user photographs himself, a display unit on the same face as the camera 121, that is, a portion of the display unit 151 on the rear face of the mobile terminal 100 in the drawing may be used. When the user photographs the object on the other side of the user, a display unit on an opposite side to the camera 121, that is, a portion of the display unit 151 on the front face of the mobile terminal 100 in the drawing may be used. For this reason, the mobile terminal 100 may use one camera 121 to photograph the object located on the opposite side of the user or to photograph the user. The camera may include a plurality of cameras having different angles of view, such as a wide angle, a super wide angle, a telephoto, and the like. In addition to the camera, the proximity sensor, a sound output unit, and the like may be located on the first rear portion 1012, and an antenna 116 may be installed on the first rear portion 1012.

The side portion 1014 may extend along edges of the first front portion 1011 and the first rear portion 1012/the second rear portion 1013 so as to surround a perimeter of the first frame 101, and may form an outer shape of the mobile terminal 100. However, as mentioned above, the second frame 102 is accommodated in the first frame 101 and is also movably coupled to the first frame 101. Thus, in order to allow a relative movement of the second frame 102 for the first frame 101, a portion of the first frame 101 needs to be opened. As well illustrated in FIG. 2, as an example, the second frame 102 is movably coupled to one of both side portions of the first frame 101, so that the first frame 101 may include a first side portion 101 a that is substantially closed and a second side portion 101 b that is disposed opposite to the first side portion 101 a and opened. Because the side portion 1014 is exposed to the outside of the mobile terminal 100, the interface unit 160 for connecting a power port or an ear jack, the user input unit 120 such as a volume button, and the like may be arranged thereon. When the side portion 1014 contains a metal material, the side portion 1014 may serve as an antenna. The second rear portion 1013 of the first frame 101 may be covered by the display unit, but may also be disposed on the front face of the display unit using a transparent material.

The second frame 102 may include a second front portion 1021 disposed at the front portion of the mobile terminal 100 and a third rear portion 1022 disposed at the rear portion of the mobile terminal 100. Like the first front portion 1011 and the first rear portion 1012 of the first frame 101, the second front portion 1021 and the third rear portion 1022 may be made of a substantially flat plate-shaped member. In addition, the second frame 102 accommodates various components therein, and should not interfere with components accommodated in the first frame 101 during a movement. Therefore, the second front portion 1021 and the third rear portion 1022 may be coupled to each other in a state of being spaced apart from each other to define a predetermined space therebetween, and may have a shape that does not interfere with the components in the first frame 101.

In addition, the display unit 151 may be bent 180 degrees while being wound inside the second frame 102 so as to be disposed on both the front face and the rear face of the mobile terminal 100. For such an arrangement of the display unit 151, the second frame 102 may include a roller 1028 rotatably disposed therein. The roller 1028 may be disposed at any position inside the second frame 102. However, the display unit 151 must be spread flat on the front face and rear face of the mobile terminal 100 in order to provide a good quality screen to the user. For such spread, an adequate tension must be provided to the display unit 151. In order to provide the adequate tension, the roller 1028 may be disposed at a first directional end of the second frame 102. Such roller 1028 may be extended in the second direction, and may be rotatably coupled to the second frame 102.

The display unit 151 may be wound on the roller 1028 while gently bending with a predetermined curvature. The flexible display unit 151 may include a first face on which an image is output and is exposed to the outside, and an inner face facing the frame on the opposite side. The roller 1028 may be installed to freely rotate in the second frame 102 while being in contact with the inner face of the display unit 151. Therefore, the roller 1028 may actually move the display unit 151 in a lateral direction, that is a direction perpendicular to a longitudinal direction of the mobile terminal 100. As will be described below, when the second frame 102 slides, the display unit 151 may move to the front face or the rear face of the mobile terminal 100 relative to the second frame 102 in different directions (i.e., the first direction D1 or the second direction D2) by the tension applied by the second frame 102. The roller 1028 may guide such movement while rotating.

In addition, the roller 1028 is disposed on a first side portion 102 a of the second frame 102, and the first side portion 102 a actually corresponds to an outermost side portion of the mobile terminal 100. When the first side portion 102 a of the second frame 102 is exposed, the display unit 151 wound on the roller 1028 may be damaged. Accordingly, the second frame 102 may include a side frame 1024 disposed on the first side portion 102 a.

The side frame 1024 may extend in a longitudinal direction of the second frame 102 to cover the first side portion 102 a, thereby protecting the roller 1028 and the display unit 151 wound on the roller 1028. That is, the side frame 1024 covers the side face of the display unit 151, and the side face is located in a third region. The first region 1511 to the third region are respectively located at specified positions and do not change in size or position, but sizes of the front face and rear face and a position of the side face of the display unit 151 are determined based on a state of a main frame.

The first region 1511 and the second region 1512 correspond to the aforementioned fixed portion, and the third region 1513 corresponds to the aforementioned variable portion. The position of the third region 1513 may vary based on the state of the mobile terminal. Because the side face is wound by the roller, the side face may be bent with a predetermined curvature, and an inner face of the side frame may have a curved face corresponding to the curvature of the side face.

The second frame 102 may have the substantially closed first side portion 102 a by such side frame 1024, and the side frame 1024 may substantially form the outer shape of the mobile terminal 100 together with the side portion 1014 of the first frame 101. In addition, in order to minimize interference with the components in the first frame 101 during the movement, the second frame 102 may include a second side portion 102 b disposed opposite to the first side portion 102 a and opened.

Such second frame 102 may be movably coupled to the first frame 101, and accordingly, may slide in the predetermined first or second direction D1 or D2 with respect to the first frame 101. More specifically, as described above, the second frame 102 may be movably coupled to the first frame 101 through the side portion of the first frame 101, precisely through the open second side portion 101 b. More specifically, the second side portion 102 b of the second frame may be disposed relatively adjacent to the first side portion 101 a of the first frame 101 to be closed. Accordingly, the first side portion 102 a of the second frame may be disposed opposite to the first side portion 101 a. Accordingly, the second side portion 102 b may be inserted into the first frame 101 through the side portion of the first frame, that is, the second side portion 101 b thereof. The first side portion 102 a may not be inserted into the first frame 101 and may always be located outside the first frame 101. Accordingly, as described above, the first side portion 102 a may form the outer shape of the mobile terminal 100. However, if necessary, such first side portion 102 a of the second frame 102 may also be inserted into the first frame 101.

Because of such positional relationship, the second frame 102 may be expanded from or contracted into the first frame 101 in a direction perpendicular to the longitudinal direction of the mobile terminal 100 or the first frame 101. That is, the first and second directions D1 and D2 may be basically directions perpendicular to the longitudinal direction of the mobile terminal 100 or the first frame 101. In one example, the first and second directions D1 and D2 may also be described as a lateral direction or a horizontal direction of the mobile terminal 100 or the first frame 101. In addition, in the movement in the first direction D1, the second frame 102 is extended from the first frame 101. Accordingly, the first direction D1 may be a direction in which the second frame 102 moves away from the first frame 101, that is, outwardly of the mobile terminal 100 or the first frame 101. On the other hand, in the movement in the second direction D2, the second frame 102 is contracted into the first frame 101. Therefore, the second direction D2 may be a direction opposite to the first direction D1. In addition, the second direction D2 may be a direction in which the second frame 102 moves to be closer to the first frame 101, that is, inwardly of the mobile terminal 100 or the first frame 101. When moved in the first direction D1, such second frame 102 may be expanded, may apply a force to the portion of the display unit 151 that was disposed on the rear face of the mobile terminal 100 to additionally dispose the portion of the display unit 151 on the front face of the mobile terminal 100, and may define a region for such additional disposition. Accordingly, the second frame 102 may switch the state of the mobile terminal 100 to the second state having a relatively expanded front face display unit 151 by the movement in the first direction D1. On the other hand, when moved in the second direction D2, the second frame 102 may be contracted to an original state, and may apply a force to the portion of the display unit 151 that was disposed on the front face of the mobile terminal 100 to return the portion of the display unit 151 to the rear face of the mobile terminal 100 again. Accordingly, the second frame 102 may switch the state of the mobile terminal 100 to the first state having a relatively reduced front face display unit 151 by the movement in the second direction D2. Therefore, the second frame 102 may selectively expose the display unit 151 on the front face of the mobile terminal 100 based on to the movement direction (i.e., the first or the second direction D1 or D2), and accordingly, switch the state of the mobile terminal 100 to the first or the second state defined above.

During such expansion and contraction in the first and the second directions D1 and D2, the second frame 102 may overlap with the first frame 101, precisely, the first front portion 1011 and the first rear portion 1012 thereof so as not to interfere with the first frame 101. More specifically, the display unit 151 may be coupled to and supported by the first front portion 1011 of the first frame 101, as described above. Accordingly, the display unit 151 does not need to be additionally supported by the second front portion 1021 of the second frame 102. When the second front portion 1021 is interposed between the first front portion 1011 and the display unit 151, the display unit 151 may rather be deformed or damaged due to friction between the second front portion 1021 that moves repeatedly. Accordingly, the second front portion 1021 may be disposed below the first front portion 1011 as illustrated well in FIG. 5. That is, a front face of the second front portion 1021 may face a rear face of the first front portion 1011. In addition, the rear face of the first front portion 1011 may be in contact with the front face of the second front portion 1021 to stably support the movement of the second frame 102.

The third rear portion 1022 of the second frame 102 may be disposed below the second rear portion 1013 of the first frame 101. That is, a front face of the third rear portion 1022 may face a rear face of the second rear portion 1013. In addition, the rear face of the second rear portion 1013 may be in contact with the front face of the third rear portion 1022 to stably support the movement of the second frame 102. By such arrangement, the third rear portion 1022 may be exposed to the outside of the first frame, precisely, of the second rear portion 1013, and may be coupled to the display unit 151.

Alternatively, when the second rear portion 1013 is made of a transparent material, the second rear portion 1013 may form an outer shape of the rear face of the mobile terminal. The second rear portion 1013 may be located rearward of the third rear portion 1022 of the second frame, and the flexible display unit may be located between the second rear portion 1013 and the third rear portion 1022 in the first state.

When the second rear portion 1013 forms the outer shape of the rear face of the mobile terminal using a material such as transparent glass, the first rear portion 1012 may be implemented using the same member as the second rear portion 1013. That is, a plate-shaped member made of the transparent glass may be partially coated such that the internal components are not visible and the coating may be omitted only for a necessary portion to arrange the camera 121, the flash, the sensing unit 140, or the like.

In addition, the second frame 102 may expand and contract the mobile terminal 100 itself, particularly, the front face of the mobile terminal 100 by the expansion and the contraction in the first and the second directions D1 and D2. The display unit 151 must move by such the expanded or contracted front face to obtain the intended first and second states. However, when fixed to the second frame 102, the display unit 151 may not be moved smoothly based on the front face of the mobile terminal 100 that is expanded or reduced. For this reason, the display unit 151 may be movably coupled to the second frame 102. More specifically, the display unit 151 may include a first side end 151 d disposed on the front face of the mobile terminal 100 and a second side end 151 e opposite to the first side end 151 d and disposed on the rear face of the mobile terminal 100. The first side end 151 d may be disposed on the front face of the first frame 101, that is, a front face of the first front portion 1011, and may be disposed adjacent to the side portion of the mobile terminal 100, that is, the first side portion 101 a of the first frame. On the other hand, because the second end 151 e is adjacent to the rear face of the mobile terminal 100, that is, the third rear portion 1022 of the second frame 102, the second end 151 e may be coupled to the third rear portion 1022 of the second frame 102 in a manner of being movable in the first and second directions D1 and D2. In addition, the display unit 151 is not structurally strong, so that a third frame 103 may be coupled to such second end 151 e. The third frame 103 may be formed of a plate-shaped member extending in the longitudinal direction of the mobile terminal 100. Accordingly, the third frame 103 may be coupled to the second frame, that is, the third rear portion 1022 of the second frame in a manner of being movable in the first and second directions D1 and D2, in place of the second end 151 e. In addition, the second frame 102 may include a slot 1025 extending in the lateral direction of the mobile terminal 100 or the second frame, that is, a direction perpendicular to the longitudinal direction of the mobile terminal 100 or the second frame. The third frame 103 may be stably moved while being guided by the slot 1025. The third frame 103 may include, for example, a protrusion inserted into the slot 1025 for the movement along the slot 1025.

Referring to FIGS. 3 to 5, in connection with the configuration of the first to third frames 101, 102, and 103, the display unit 151 may include the first region 1511 extending from one side of the display 151, that is, the first side end 151 d to the second side end 151 e opposite to the first side end 151 d with a predetermined length, and the second region 1512 disposed opposite to the first region 1511 and extending from the second side end 151 e to the first side end 151 d with a predetermined length. In addition, the display unit 151 may include the third region 1513 disposed between the first and the second regions 1511 and 1512. Such first to third regions 1511, 1512, and 1513 may be connected to each other, and may form the continuous body of the display unit 151. In addition, as described above, for the movement of the third region 1513 to the front face or rear face of the mobile terminal 100 based on the movement direction of the second frame 102, the first region 1511 may be fixed so as not to move on the front face of the mobile terminal 100, and the second region 1512 may be provided movably on the rear face of the mobile terminal. Such configuration of the display unit 151 will be described in more detail below.

The first region 1511 may be disposed on the front face of the mobile terminal 100, and more specifically, on the front face of the first frame 101, that is, the first front portion 1011. The first region 1511 is fixed to the first frame 101, that is, the front face of the first front portion 1011 so as not to move even when the second frame 102 moves. Accordingly, the first region 1511 may always be exposed on the front face of the mobile terminal 100. The third region 1513 may be adjacent to the first region 1511, and may extend into the second frame 102 to be wound on the roller 1028. The third region 1513 may continuously extend out of the second frame 102 again and partially cover the second frame 102, that is, the rear face of the third rear portion 1022. In one example, the second frame 102, that is, the third rear portion 1022 is adjacent to the first frame 101, that is, the second rear portion 1013 and forms a rear casing of the mobile terminal 100 together with the first frame 101, that is, the second rear portion 1013. Therefore, it may be described that the third region 1513 is also disposed on the rear face of the first frame 101.

The second region 1512 may be adjacent to the third region 1513, and may be disposed on the rear face of the mobile terminal 100, and more specifically, on the second frame, that is, the rear face of the third rear portion 1022 of the second frame. The second region 1512 may be coupled to the third frame 103 rather than directly coupled to the second frame 102. As shown in (b) in FIG. 4, the slot 1025 extending in the lateral direction (i.e., the direction perpendicular to the longitudinal direction of the mobile terminal 100) may be defined in the second frame 102, that is, the third rear portion 1022, and the third frame 103 may move along the slot 1025. In (b) in FIG. 4, the slot 1025 is illustrated as being defined in the rear face of the second frame 102, but may be defined in a side face of the second frame 102. The second region 1512 may move in the first or second direction D1 or D2 with respect to the second frame 102 together with the third frame 103, but a range of the movement of the second region 1512 may be limited to the rear face of the mobile terminal 100 by the slot 1025. That is, the second region 1512 may not move out of the second frame 102 even when the second frame 102 expands or contracts, and may move along the slot 1025 within the second frame 102 by an extended or contracted length of the second frame 102. Thus, the second region 1512 may always be exposed on the rear face of the mobile terminal 100.

As a result, the first region 1511 may be disposed on the front face of the mobile terminal 100 and may always be exposed to the front face regardless of the movement of the second frame 102. The second region 1512 may be disposed on the rear face of the mobile terminal 100 and may always be exposed to the rear face regardless of the movement of the second frame 102. In addition, the third region 1513 may be disposed between the first and second regions 1511 and 1512, and may be selectively disposed on the front or rear face of the mobile terminal 100 based on the movement directions D1 and D2 of the second frame 102.

Because of such selective disposition of the third region 1513, as shown in FIG. (b) in FIG. 4, the second rear portion 1013 of the first frame 101 may be covered by the second and third regions 1512 and 1513 of the display unit 151 and the third rear portion 1022 in the first state, but may be exposed to the outside of the mobile terminal 100 in the second state because the third region 1513 moves to the front face of the mobile terminal 100 and the third rear portion 1022 also moves in the first direction D1. In addition, the second front portion 1021 of the second frame 102 may be disposed below the first front portion 1011 of the first frame 101 in the first state, but the second front portion 1021 may be moved out of the first frame 101 in the second state to support the third region 1513 of the display unit 151 disposed on the front face of the mobile terminal 100.

The first and second regions 1511 and 1512 are always respectively arranged on the front face and the rear face of the mobile terminal 100, so that curvatures of the first region 1511 and the second region 1512 may not be changed and maintained in a flat basic state. However, the third region 1513 may be wound on the roller 1028 and bent within the second frame 102. When switching from the first state to the second state, the third region 1513 may be extended from the second frame 102 to the front face of the mobile terminal 100 while being wound in one direction on the roller 1028. On the other hand, when switching from the second state to the first state, the third region 1513 may contract to the second frame 102 from the front face of the mobile terminal 100 while being wound on the roller 1028 in the opposite direction. At the same time, the third region 1513 may return to the rear face of the mobile terminal 100 from the second frame 102. Only a specific position of a foldable mobile terminal in a form of being unfolded like a book is repeatedly folded, so that the specific position thereof is likely to be damaged. On the other hand, a deformed portion of the flexible display unit 151, that is, a portion wound on the roller 1028 may be changed based on the first and second states of the mobile terminal 100, that is, the movement of the second frame 102. Therefore, the mobile terminal 100 according to the present disclosure may significantly reduce deformation and fatigue repeatedly applied to a specific portion of the display unit 151, thereby preventing damage to the display unit 151.

Based on the above-described configuration, an overall operation of the mobile terminal 100 will be described as follows. As an example, the switching of the state may be manually performed by the user, and an operation of the mobile terminal 100 during such manual state switching will be described. However, operations of the first to third frames 101 to 103 and the display unit 151 to be described below may be performed in the same manner when a power source other than the force of the user is used, for example, when the driving unit 200 to be described below is applied.

As shown in (a) in FIG. 3, (a) in FIG. 4, and (a) in FIG. 5, the second frame 102 is completely contracted into the first frame 102 in the first state. Therefore, only the first region 1511 of the display unit 151 fixed to the front face of the first frame 101 may be exposed to the front face of the mobile terminal 100. Such first region 1511 may be fixed to and supported by the first frame 101, that is, the first front portion 1011 of the first frame 101. In addition, a great portion of the third region 1513 is disposed on the rear face of the mobile terminal 100 together with the second region 1512, and may be disposed in the second frame 102 in a state of being partially wound on the roller 1028. The third region 1513 on the rear face of the mobile terminal 100 may be supported by the second frame, that is, the third rear portion 1022 of the second frame. The second region 1512 may be fixed by the third frame 103 disposed on the second frame (i.e., the third rear portion 1022), and may be movably coupled to the second frame 1012.

In such first state, when the second frame 102 moves in the first direction D1, the mobile terminal 100 may be switched to the second state. As shown in (b) in FIG. 3, (b) in FIG. 4, and (b) in FIG. 5, the second frame 102 may be extended from the first frame 101 by the movement in the first direction D1, and may increase an overall size of the mobile terminal 100, in particular, a size of the front face of the mobile terminal 100. During such movement in the first direction D1, the second frame 102 may apply the force, that is, the tension, to the display unit 151 in the first direction D1. The display unit 151 is fixed to the first frame 101, but is movably coupled to the second frame 102 using the third frame 103. Thus, the third region 1513 may be rolled out from the roller 1028 in the second frame 102 to the front face of the mobile terminal 100 by the force applied by the second frame 102. That is, the third region 1513 may be withdrawn or pulled out, extended, or moved out from the second frame 102. At the same time, the third region 1513, particularly a portion of the third region 1513 disposed on the rear face of the mobile terminal 100, may be rolled into the second frame 102, or inserted or pushed in, retracted, or moved into the second frame 102. An entirety of the third region 1513 may not be withdrawn from the second frame 102 to the front face of the mobile terminal 100, and a portion of the third region 1513 may still be disposed in the second frame 102 in a state of being wound on the roller 1028. In addition, for the smooth movement of such third region 1513, the second region 1512 may also move in the first direction D1 with respect to the second frame 102 along with the third frame 103. In addition, as described above, the second region 1512 and the third frame 103 may be constrained to the second frame 102 and move in the first direction D1 with respect to the first frame 101 together with the second frame 102. Accordingly, the second region 1512 and the third frame 103 may move relatively in the first direction D1 with respect to the first frame 101 as well as to the second frame 102. Accordingly, a moved distance of the second region 1512 and the third frame 103 may be greater than a moved distance of the second frame 102. Therefore, because of the movement of the long distance in the first direction D1 of the second region 1512, the third region 1513 may be smoothly expanded to the front face of the mobile terminal 100. In addition, for the movement of the third region 1513 proportional to the expansion of the second frame 102, the movement of the second region 1512 and the third frame 103 in the first direction D1 may be simultaneously performed with the movement of the third region 1512 and the second frame 102 so as to be proportional to the movement of the third region 1512 and the second frame 102.

When the second frame 102 is completely expanded in the first direction D1, the first and third regions 1511 and 1513 are arranged on the front face of the mobile terminal 100, and only the second region 1512 may be disposed on the rear face of the mobile terminal 100. Such first and third regions 1511 and 1513 may be supported by the first frame (i.e., the first front portion 1011 thereof) and the second frame (i.e., the second front portion 1021 thereof). In addition, the second frame 102, that is, the third rear portion 1022 thereof may expose the second rear portion 1013 of the first frame while expanding in the first direction D1 and may support the moving third region 1513. Therefore, in the second state, the mobile terminal 100 may have the expanded front face display unit 151.

On the other hand, when the second frame 102 moves in the second direction D2 in the second state, the mobile terminal 100 may return to the first state again as illustrated in (a) in FIG. 3, (a) in FIG. 4, and (a) in FIG. 5. The second frame 102 may be contracted into the first frame 101 by the movement in the second direction D2, and may reduce the overall size of the mobile terminal 100, in particular, the front face of the mobile terminal 100. During such movement of the second frame 102, the movement of the display unit 151 may be performed in a reverse order to the movement in the first direction D1 described above. Briefly, the third region 1513 may be rolled into the second frame 102 and wound on the roller 1028 from the front face of the mobile terminal 100 or may be inserted, retracted, or moved into the second frame 102. At the same time, the third region 1513 may be rolled out, withdrawn or pulled out, or moved out to the rear face of the mobile terminal 100 from the roller 1028 of the second frame 102. Not the entirety of the third region 1513 is withdrawn from the second frame 102 to the rear face of the mobile terminal 100. A portion of the third region 1513 may still be disposed in the second frame 102 in a state of being rolled on the roller 1028. In addition, for the smooth movement of such third region 1513, the second region 1512 may also move in the second direction D2 with respect to the second frame 102 along with the third frame 103. The second region 1512 and the third frame 103 may be constrained to the second frame 102 and move in the second direction D2 with respect to the first frame 101 together with the second frame 102. Accordingly, the second region 1512 and the third frame 103 may move relatively in the second direction D2 with respect to the first frame 101 as well as the second frame 102. Accordingly, a moved distance of the second region 1512 and the third frame 103 in the second direction D2 may be greater than a moved distance of the second frame 102 in the second direction D2. Therefore, because of the movement of the long distance of the second region 1512, the third region 1513 may smoothly return to the rear face of the mobile terminal 100. In addition, for the movement of the third region 1513 proportional to the contraction of the second frame 102, the movement of the second region 1512 and the third frame 103 in the second direction D2 may be simultaneously performed with the movement of the third region 1512 and the second frame 102 so as to be proportional to the movement of the third region 1512 and the second frame 102. When the second frame 102 is completely contracted in the second direction D2, the mobile terminal 100 may be switched to the first state as described above and may have the front face display unit 151 that is relatively contracted in the first state compared to the second state.

FIG. 6 is a rear face view of some components of a mobile terminal according to one embodiment. Specifically, (a) in FIG. 6 is a view corresponding to the first state of the mobile terminal, and (b) in FIG. 6 is a view corresponding to the second state of the mobile terminal.

The mobile terminal 100 according to an embodiment may further include a spring member 310 to prevent the flexible display panel 151 from being wrinkled. FIG. 6 is illustrated by omitting the flexible display panel 151 for convenience of description. A configuration of the flexible display panel 151 may refer to FIG. 7 below.

The spring member 310 can prevent the flexible display panel 151 from being wrinkled while the second frame 102 of the mobile terminal 100 moves with respect to the first frame 101. Specifically, the spring member 310 can provide a constant force to the third frame 103 in a second direction B opposite to a first direction A.

FIG. 7 is an exploded view of some components of the mobile terminal 100 according to one embodiment. The mobile terminal 100 according to an embodiment may include the first frame 101, the second frame 102, the third frame 103, the flexible display panel 151, the driving unit 200, and the spring member 310.

The first frame 101 may include the first front portion 1011 constituting a front face of the first frame 101, the second rear portion 1012 constituting a rear face of the first frame 101, and the third rear portion 1013 protruding from the second rear portion 1012 in a rear face direction. The first front portion 1011 and the second rear portion 1012 may define a mounting space therebetween.

The second frame 102 may include the third rear portion 1022 disposed on the rear face of the first frame 101 and coupled to the rear face of the first frame 101 in a manner of being movable in the first direction A, and a first roller 1028 disposed at an end in the first direction A of the third rear portion 1022. Specifically, the third rear portion 1022 may be disposed such that at least a portion thereof overlaps a rear face of the second rear portion 1012.

The third frame 103 may be disposed on a rear face of the third rear portion 1022 and may be coupled to the rear face of the third rear portion 1022 in a manner of being movable in the first direction A or in the second direction B opposite to the first direction A.

The flexible display panel 151 may be disposed to surround the first roller 1028, so that one end of the flexible display panel 151 may be disposed on the front face of the first frame 101 and the other end thereof may be disposed on the third frame 103. Specifically, the flexible display panel 151 may be disposed to cover a front face of the first front portion 1011 and cover the first roller 1028 to cover a rear face of the third frame 103.

The driving unit 200 may drive the second frame 102 from the first frame 101 in the first direction A or in the second direction B that is opposite to the first direction A. A state in which the second frame 102 is maximally moved from the first frame 101 in the first direction A may correspond to the first state. A state in which the second frame 102 is maximally moved from the first frame 101 in the second direction B, which is opposite to the first direction A, may correspond to the second state. Specifically, in the second state, the third rear portion 1022 may cover an entirety of the rear face of the second rear portion 1012 and be in contact with the third rear portion 1013.

A movement of each component in response to the driving of the driving unit 200 is as follows. When the second frame 102 moves in the first direction A with respect to the first frame 101, the third frame 103 may move in the first direction A with respect to the second frame 102. This is because the flexible display panel 101 is not a tensioned. Conversely, when the second frame 102 is moved in the second direction B with respect to the first frame 101, the third frame 103 may move in the second direction B with respect to the second frame 102.

The spring member 310 may provide the constant force to the third frame 103 in the second direction B. The force provided by the spring member 310 may correspond to a force of pulling the flexible display panel 151 from one side. The flexible display panel 151 may be prevented from being wrinkled using the force provided by the spring member 310. Specifically, the spring member 310 may exert the constant force in the second direction B on the third frame 103 even when the mobile terminal 100 is in the first state or in the second state. In addition, the spring member 310 may exert the constant force in the second direction B even when the third frame 103 moves in the first direction A. In addition, the spring member 310 may exert the constant force in the second direction B even when the third frame 103 moves in the second direction B. As the spring member 310 used in the mobile terminal 100 according to an embodiment, a constant force spring may be used. The constant force spring will be described below.

FIGS. 8 and 9 are views for describing some components of a mobile terminal according to one embodiment. Specifically, FIGS. 8 and 9 are diagrams for describing a configuration and a characteristic of the spring member 310.

The spring member 310 may include a fixed shaft 311, and a spiral spring 312 disposed to be wound around or unwound from the fixed shaft 311 to generate a constant attractive force while being wound around or unwound from the fixed shaft 311. Additionally, the spring member 310 may include a housing 313 in which the spiral spring 312 may be mounted in a wound state. Specifically, (a) in FIG. 8 shows a state in which the spiral spring 312 of the spring member 310 is wound, (b) in FIG. 8 is a perspective view for illustrating an interior of the housing 313 of the spring member 310, and (c) in FIG. 8 shows an unwound state of the spiral spring 312 of the spring member 310.

The spiral spring 312 may be wound around or unwound from the fixed shaft 311 while rotating along the fixed shaft 311. Specifically, the fixed shaft 311 may not rotate, and an end of the spiral spring 312 may not be fixed to the fixed shaft 311 and may rotate along the fixed shaft 311. In some cases, the fixed shaft 311 may rotate, and the end of the spiral spring 312 may be fixed to the fixed shaft 311. The above structure is for generating a constant force in a winding direction while the spiral spring 312 is being unwound or wound or in the unwound or wound state of the spiral spring 312. The spring member 310 having such characteristic may be the constant force spring.

Specifically, FIG. 9 is a view for describing a characteristic of the constant force spring. The constant force spring may be a spring that provides a constant force fc in a winding direction while being unwound or wound in a state of being unwound by a length equal to or greater than a first length L1. The constant force spring may provide the constant force fc in the winding direction until being in a state of being unwound by a second length L2.

FIG. 10 shows an enlarged view and a cross-sectional view of a portion C in FIG. 6. FIG. 11 shows an enlarged view and a cross-sectional view of a portion D in FIG. 6. In the spring member 310, the fixed shaft 311 may be fixed to the third frame 103, and the end of the spiral spring 312 may be fixed to the third rear portion 1022 and wound in the first direction A and unwound in the second direction B. In this connection, the second direction B may be opposite to the first direction A.

Specifically, the end of the spiral spring 312 may be fixed to a fastening portion 1027 disposed on the third rear portion 1022. In this case, the third rear portion 1022 may include a guide groove 1029 a recessed in a front face direction such that the spring member 310 may move.

The spring member 310 may connect the frame 103 and the third rear portion 1022 with each other such that the spiral spring 312 is maintained in the state of being unwound by the length equal to or greater than the first length L1 when the spiral spring 312 provides a constant attractive force in the state of being unwound by the length equal to or greater than the first length L1. Specifically, referring to (a) in FIG. 10, the third frame 103 may be maintained in a state of being maximally moved in the second direction B, which is opposite to the first direction A, with respect to the third rear portion 1022 in the first state. The spring member 310 may connect the third frame 103 and the third rear portion 1022 with each other in the state in which the spiral spring 312 is unwound by the length equal to or greater than the first length L1 in the first state.

The spring member 310 may connect the frame 103 and the third rear portion 1022 with each other such that the spiral spring 312 is maintained in a state of being unwound by a length equal to or less than the second length L2 when the spiral spring 312 provides the constant attractive force in the state of being wound by the length equal to or less than the second length L2. Specifically, referring to (a) in FIG. 11, the third frame 103 may be maintained in a state of being maximally moved in the first direction A with respect to the third rear portion 1022 in the second state. The spring member 310 may connect the third frame 103 and the third rear portion 1022 with each other in a state in which the spiral spring 312 is unwound by the length equal to or less than the second length L2 in the second state.

FIG. 12 is a front view of some components of a mobile terminal according to one embodiment. Specifically, (a) in FIG. 12 is a view corresponding to the first state of the mobile terminal, and (b) in FIG. 12 is a view corresponding to the second state of the mobile terminal. The third rear portion 1022 may include a slit 1029 b communicating the rear face and the front face of the third rear portion 1022 with each other such that the spiral spring 102 is disposed on the front face of the third rear portion 1022.

The spring member 310 may be disposed such that the fixed shaft 311 is fixed to the third rear portion 1022 and the end of the spiral spring 312 is fixed to the third frame 103 and unwound in the first direction. Specifically, the third frame 103 may include an engaging portion 1031 protruding in the rear face direction, and the engaging portion 1031 may be disposed to penetrate the slit 1029 b. The spiral spring 312 may be disposed to be wound around or unwound from the fixed shaft 311 fixed to the third rear portion 1022, and the end of the spiral spring 312 may be fixed to the engaging portion 1031 disposed on the third frame 103.

FIG. 13 is a cross-sectional view of some components of a mobile terminal according to one embodiment. Specifically, (a) in FIG. 13 illustrates a cross-section taken along a line E-E′ in FIG. 10, and (b) in FIG. 13 illustrates a cross-section taken along a line F-F′ in FIG. 12.

When the fixed shaft 311 of the spring member 310 is fixed to the third frame 103, the third rear portion 1022 may include the guide groove 1029 a as a space along which the spring member 310 moves. The guide groove 1029 a may be defined along the first direction A. When the fixed shaft 311 of the spring member 310 is fixed to the third rear portion 1022, the third rear portion 1022 may include the slit 1029 b penetrating the front face and the rear face of the third rear portion 1022. The slit 1029 b may be defined along the first direction A.

FIG. 14 is a rear face view of some components of a mobile terminal according to one embodiment. FIG. 15 is a cross-sectional view taken along a line G-G′ in FIG. 14. FIG. 16 is a view for describing some components of a mobile terminal according to one embodiment. Hereinafter, a description will be given focusing on a difference from FIG. 6.

In the mobile terminal 100 according to an embodiment, the spring member 310 may be disposed differently from FIG. 6. As a fixed shaft of the spring member 310, a shaft 1028 a of the first roller 1028 may be used. Specifically, the spiral spring 312 may be wound around or unwound from the shaft 1028 a of the first roller 1028.

The spiral spring 312 may be disposed to surround the shaft 1028 a of the first roller 1028 and may be disposed to be unwound in the second direction B, which is opposite to the first direction A. The spiral spring 312 may be fixed directly to the third frame 103 or may be connected to the third frame 103 through a connector.

In order for the spiral spring 312 to be fixed directly to the third frame 103, the spiral spring 312 is necessary to be fixed to the third frame 103 in a state of being maximally unwound from the shaft 1028 a of the first roller 1028 in the first state. This is because the third frame 103 is spaced apart from the first roller 1028 in the second direction B in the first state. In this case, the spiral spring 312 may be maintained in a state of being maximally wound around the shaft 1028 a of the first roller 1028 in the second state. However, the spiral spring 312 may be disposed to be wound and unwound by a length between the first length L1 and the second length L2.

In order for the spiral spring 312 to be fixed indirectly to the third frame 103, the spring member 310 may additionally include a wire 314 for connecting the end of the spiral spring 312 with the third frame 103, and a shaft 315 that is fixed to the third rear portion 1022 and surrounded by the wire 314 such that both ends of the wire 314 are directed in the first direction A. In this case, the spiral spring 312 may be maintained in the state of being maximally wound around the shaft 1028 a of the first roller 1028 in the first state, and maintained in the state of being maximally unwound from the shaft 1028 a of the first roller 1028 in the second state.

The shaft 315 may further include a bearing 3151 that rotates in response to the movement of the wire 314. This is to prevent a force required to move the second frame 102 from increasing due to friction between the wire 314 and the shaft 315. The first roller 1028 may be divided into two regions. A first region may be a region that rotates in contact with the rear face of the flexible display panel 151. A second region may be a region around which the spiral spring 312 is wound. In this case, a diameter of the second region may be smaller than a diameter of the first region.

In addition, the first roller 1028 may rotate in the first region and may not rotate in the second region. The second region may be a region where the shaft 1028 a of the first roller 1028 is exposed, and the first region may be a region including a component that rotates on the shaft 1028 a of the first roller 1028. In some cases, the shaft 1028 a of the first roller 1028 may also rotate.

The above detailed description should not be construed as limiting in all aspects and should be considered illustrative. The scope of the present disclosure should be determined by rational interpretation of the appended claims, and all changes within the equivalent scope of the present disclosure are included in the scope of the present disclosure. 

What is claimed is:
 1. A mobile terminal comprising: a first frame; a second frame including a third rear portion coupled to a rear face of the first frame and being movable in a first direction, and including a roller disposed at an end in the first direction of the third rear portion; a third frame coupled to a rear face of the third rear portion and being movable in the first direction; a flexible display panel surrounding the roller and having one end on a front face of the first frame and another end disposed on the third frame; a driving unit configured to drive the second frame from the first frame in the first direction or in a second direction reverse to the first direction; and a spring member connecting the second frame to the third rear portion of the second frame and configured to provide a constant force in the second direction to the third frame.
 2. The mobile terminal of claim 1, wherein the spring member includes: a fixed shaft; and a spiral spring wound around or unwound from the fixed shaft, and wherein the spiral spring generates a constant attractive force while being wound around or unwound from the fixed shaft.
 3. The mobile terminal of claim 2, wherein the fixed shaft is fixed to the third frame, an end of the spiral spring is fixed to the third rear portion, and the spiral spring is wound in the first direction, or wherein the fixed shaft is fixed to the third rear portion, the end of the spiral spring is fixed to the third frame, and the spiral spring is unwound in the first direction.
 4. The mobile terminal of claim 2, wherein the third rear portion includes a guide groove recessed in the rear face of the third rear portion in a direction of a front face of the third rear portion such that the spiral spring is disposed on the rear face of the third rear portion.
 5. The mobile terminal of claim 2, wherein the third rear portion includes a slit for communicating the rear face and a front face of the third rear portion with each other such that the spiral spring is disposed on the front face of the third rear portion.
 6. The mobile terminal of claim 2, wherein, when the spiral spring is in a state of being unwound by a length equal to or greater than a first length, the spring member connects the third frame and the third rear portion with each other such that the spiral spring is maintained in the state of being unwound by the length equal to or greater than the first length.
 7. The mobile terminal of claim 6, wherein the third frame is maintained in a state of being maximally moved in the second direction with respect to the third rear portion in a first state, and wherein the spring member connects the third frame and the third rear portion with each other in the state where the spiral spring is unwound by the length equal to or greater than the first length in the first state.
 8. The mobile terminal of claim 6, wherein, when the spiral spring is in a state of being unwound by a length equal to or less than a second length, the spring member connects the third frame and the third rear portion with each other such that the spiral spring is maintained in the state of being unwound by the length equal to or less than the second length.
 9. The mobile terminal of claim 8, wherein the third frame is maintained in a state of being maximally moved in the first direction with respect to the third rear portion in a second state, wherein the spring member connects the third frame and the third rear portion with each other in the state where the spiral spring is unwound by the length equal to or less than the second length in the second state.
 10. The mobile terminal of claim 2, wherein the fixed shaft is a shaft of the roller.
 11. The mobile terminal of claim 10, wherein the spring member includes: a wire connecting an end of the spiral spring to the third frame; and a shaft fixed to the third rear portion and surrounded by the wire such that both ends of the wire are directed in the first direction.
 12. The mobile terminal of claim 11, wherein the shaft includes a bearing rotating in response to a movement of the wire.
 13. The mobile terminal of claim 10, wherein the roller includes: a first region rotating in contact with a rear face of the flexible display panel; and a second region wound by the spiral spring.
 14. The mobile terminal of claim 13, wherein a diameter of the second region is equal to or smaller than a diameter of the first region in a state where the spiral spring is maximally wound.
 15. The mobile terminal of claim 13, wherein the roller does not rotate in the second region.
 16. The mobile terminal of claim 1, wherein the spring member comprises a spiral spring having one end connected to the roller such that when the roller rotates in a first rotating direction, the spiral spring is wound around the roller and when the roller rotates in a second rotating direction opposite to the first rotating direction, the spiral spring is unwound from the roller.
 17. The mobile terminal of claim 16, wherein another end of spiral spring is fixed directly to the third frame.
 18. The mobile terminal of claim 16, wherein the other end of the spiral spring is connected to the third frame via a wire connecting the other end of the spiral spring to a connector mounted on the third frame.
 19. The mobile terminal of claim 18, wherein the third rear portion of the second frame comprises a bearing shaft protruding from the third rear portion.
 20. The mobile terminal of claim 19, wherein the wire is wound on the bearing when the second frame is driven from the first frame in the first direction or in the second direction reverse to the first direction. 